Method of forming hermetically sealed metal cans



June 12, 1934. .J. J. MCLH'INNEY 1,962,280

METHOD OF FORMING HERMETICALLY SEALED METAL CANS Filed June 23, 1930 Patented June 12, 1934 Uhll'ifh STATES PATENT FFEQ 'METHGD OF FORMING HERTMETICALLY SEALED METAL CANS John .15. McLhinney, Western Springs, 111., as-

signor to Continental Can Company,

Inc.,

1 Claim.

angle flange at both ends thereof, and a can end is double seamed to one end of the can body and after the can body is filled the other end is double seamed thereto. It has been found in prac-- tice that when a right-angle. flange is formed on the can body by the manufacturer, the solder bond joining the lapped end portions of the seam is put under strain so that the solder bond after an interval of time will rupture.

An object of the present invention is to provide a method of making cylindrical cans wherein the body is provided with a right-angle flange by the packer so that the end for closing the body may be attached thereto at a relatively short interval of time after the flange is formed.

A further object of the invention is toprovide a method of making cylindrical cans where the open end of the can body flaredin the region to be flanged for reinforcing the same to facilitate shipping handling of the cans without the open ends being unduly collapsed.

In the drawing which shows by way of illustration the various steps of the method embodying the invention:

Figure 1 is a view showing more or less diagrammatically a cylindrical can body, the dies which engage the can body for forming a rightangle flan e at one end and a reinforcing flange at the other end;

Fig. 2 is a similar view showing the can body as having been provided with'the right-angle flange and the reinforcing flange;

Fig. 3 is a view showing the can with the bottom end thereof double seamed to the can body;

Fig. 4 is a view showing the right-angle flange as applied to the can body by the packer;

Fig. 5 shows the can filled and with the closing or top end double seamed thereto;

Fig. 6 is an enlarged side View of the upper por tion of the can body in the region of the side seam before it is flanged;

Fig. '7 is a sectional view on the line 7-7 of Fig. 6, and.

Fig. 8 is a sectional view on the line 88 of Fig. 6.

The invention is directed to a method of making cans from metal which are hermetically sealed by the double seaming of the ends thereto. The

body is cylindrically formed and is or" the ordinary construction. It may have its side edges joined by a. seam which is lapped throughout its entire extent or by a seam which is lapped at the ends and interlocked between the ends. This can body is provided with a right-angle flange at one end and simultaneously therewith a reinforcing flared portion in the region which is sub sequently formed into a right-angle flange. The bottom end is attached to this rightangle flange on the body by double seaming. A closing end is also provided, but is not attached to the body. This finishes the can so far as the manufacturer is concerned. The can thus completed and the ends therefor are shipped to the packer. The packer provi es the body with a right-angle flange at the open end and after the can is fllled the can end is double seamed to this right-angle flange for hermetically closing the can. By this method the flanging of the open end of the can does not occur until after the shipping of the can and Within a short interval of the before the closing end is to be attached thereto.

Referring more in detail to the drawing, the invention shown as applied to a cylindrical can which includes a can body 1 rolled into a cylinder. When a locked and lapped seam is used then the side edges of the blank forming the body are interiolded as indicated at 2 in 6 and 8, while the end portions of the side edges are lapped as indicated at 3 in Figs. 6 and '7. The side seam soldered throughout its length and thus the lapped parts are joined solely by a solder bond. In the usual practice a can body thus formed is provided with a right-angle flange at the opposite ends thereof, and these flanges are simultaneously formed by flanging dies. Gne of the hanging dies is shown diagrammatically at 4 in Fig. 2 of the drawing. Said die is provided with a central projecting portion 5 which leads to a curved surface 6 terminating in a vertical wall 7. As the die is forced into the end of the can body the metal in the end will be turned or rolled outwardly into a flange 8 which is substantially at right angles to the body wall. This rolling of the metal outwardly into a flange of course expands the metal inasmuch as the outer diameter of the flange is greater than the diameter of the can body. This expanding of the metal in the region of the lapped portions 3 places the solder bond under a severe strain. It has been found in practice that the flanging operation does not fracture the solder bond at the time when the flange is formed but when these bodies thus flanged are shipped and stored that after an interval of time the solder bond snaps or is ruptured. No matter how careful the can may be inspected by the manufacturer this rupturing of the solder bond during shipping or after the can has been shipped cannot be detected by the manufacturer and often results in leaks. The present invention is directed to a method of forming the cans whereby this right-angle flanging of the open end during shipping or storing of the same after it is flanged for a long interval of time is avoided. According to the present method the can body after it is formed is provided with a right-angle flange at one end only thereof. The other end is provided with a flared portion 9 in the region where the right-angle flange is to be formed. This is done by dies, one of which is diagrammatically illustrated at 10 in the drawing. Said die has a central projecting portion 11 which leads into a curved portion 12 terminating at a vertical wall 13. This flared portion 9 curves outwardly only to a slight extent and the flaring of the end places the solder bond at the lapped portion of the side seam under very little tension which is not severe enough to result in a rupturing of the solder bond during handling or during storing. The flared end of the can body however is reinforced to such an extent that during handling it will not collapse beyond the elastic limit of the metal and can be readily returned to a circular shape. A flared end such as shown in the drawing will stand bending strain even much better than a right-angle flange which is likely to become cracked or broken under severe crushing strain.

This right-angle flange which is of the usual construction and the flared end of the body which is believed to be new with applicant are both produced by the manufacturer and are preferably simultaneously formed on the can body by cooperating flanging dies. The limiting walls on the dies insure that after one end is completed the other is forced so that it will be likewise completed, forming a full right-angle flange at one end and the full desired flare at the other end.

A can end lat is then joined to the right-angle flange portion or" the can body by a double seam 15. An end is formed ready to be attached to the other end of the can body but is not secured thereto. The can is then shipped to the packer. It may be stored for any length of time, and there will be no snapping or rupturing of the solder bond between the lapped end portions of the metal in the side seam. The packer is of course supplied with the necessary machine for forming a right-angle flange on this open end of the can body. This is preferably done at the time when the can is to be filled and closed. In Fig. 4 of the drawing a flared end is shown as changed into a right-angle flange end indicated at 16. The can is then filled after which the can end 17 is secured to this right-angle flange 16 by a double seam 18.

From the above it will be apparent that a new method has been devised for producing metal cans wherein the losses incident to the rupturing of the solder bond at the lapped portion of the side seam are reduced to a minimum. The flanging of the open end of the can at the packers insures that the closing end is double seamed to the right-angle flange formed without the solder bond becoming ruptured either through shipment or through long standing whereby the stresses and strains set up during the flanging operation finally result in a fracturing of the solder bond. Furthermore this flanging of the can by the packer insures a uniformity of height to the cans, and also a uniformity in the forming of the flange and the forming of the end of the can for the attachment of the closing end thereto. Then again, the can after it is flanged is not subjected to the crushing forces incident to shipment, and the flanges are not broken but remain intact, as well as the solder bond remains intact.

While I have referred to the flange as a right angle flange, it will be understood that the angle to which the flange is turned may be varied but it should be preferably substantially at a right angle; it may be slightly greater or slightly less than a right angle. While I have referred to the use of solder, it will be understood that this is not restricted to any special form of solder. Any

bonding material may be used that is suitable for joining metal parts.

Having thus fully described my invention, what I claim as new and desire to secure by Letters to place the solder bond under excessive tension, 1.

providing said flared end of the can body with a substantially right angle flange immediately before filling and double seaming a can end to said last named flange for hermetically closing and 

